Water cooled platform and method of repairing copings employing the same



United States Patent Albert R. Benbow;

Donald J. Suray. Weirton, W. Va. 802,41 1

Feb. 26, 1969 Dec. 29, 1970 National Steel Corporation a corporation ofDelaware Inventors Appl. No. Filed Patented Assignee WATER COOLEDPLATFORM AND METHOD OF REPAIRING COPINGS EMPLOYING THE SAME 12 Claims, 6Drawing Figs.

US. Cl 165/47, /180, 122/498, /67, 165/168, 165/170,

Int. Cl. F23m 5/08, F28f 3/12 Field ofSearch v. 165/47, 67,

[56] References Cited UNITED STATES PATENTS 312,578 2/1885 Nightengale l10/180X 2,209,561 7/1940 Curtis 165/170X 2,627,289 2/1953Berthe1sen..... IOU/93X 2,627,290 2/1953 Berthelsen 100/93X PrimaryExaminer-Albert W. Davis, Jr. Attorney-Shanley and O'Neil ABSTRACT: Animproved water-cooled platform adapted to be placed temporarily across atop-opening furnace. such as a soaking pit, for the purpose ofpermitting workmen to make repairs to the coping without cooling downthe furnace. The invention also provides a novel method of makingrepairs to the coping of soaking pits and other types of top-openingfurnaces without cooling down the furnaces wherein a watercooledplatform is employed to protect the workmen.

PATENTEU UEEZS I976 SHEET 1 UF 3 ENVEN'H'ORS ALBERT R. BENBOW DONALD J.SURAY ATTORNEYS PAIENTED 115029 I970v SHEET 2 0F 3 mvmwoms R. BENBOWALBERT DONALD J. SURAY ATTORNEYS PATENTED 05229 |970 SHEET 3 BF 3 WATERCOOLED PLATFORM AND METHOD OF REPAIRING COPINGS EMPLOYING THE SAMEBACKGROUND OF THE INVENTION Top opening or pit furnaces are usedextensively in the steel ndustry for the heating and/or melting offerrous metal charge =tocks. For instance, top-opening soaking pits areused to rniformly heat steel ingots to a desired rolling temperature mmto delivering to a hot-rolling mill. The ingots are usually ieated to atemperature between about 2150 F. and 2 /50 F.,

ind thus the soaking pits are operated under severe temperaureconditions.

The construction and operation of soaking pits is disclosed n numerouspublications. For example, various types of top- Jpening soaking pitsare disclosed on Pages 6l9624 of the text The Making, Shaping andTreating of Steel, 8th Edition (1964), and in US. Pat. Nos.v 2,474,504,2,839,290 and 3,378,247, the teachings of which are incorporated hereinby reference.

Most soaking pits in use today are approximately rectangular inconfiguration, and have reinforced refractory walls which may beconstructed of silica refractory shapes. The

soaking pits have a depth which is sufficient to allow steel ingots tobe heated in an upright position, and grooved coping )locks are used tocap the walls. The grooves in the coping )locks form a continuous trougharound the top of the soaking )it, andsand or other refractory materialin finely divided orm is used to fill the coping trough.

Thetop of the soaking pitis provided with a removable 'efractory coverwhich rests on the coping blocks. The cover ms a continuous downwardlyprojecting lip around the edge which extends into the sand in the copingtrough to thereby form a seal and prevent entry of air into the interiorof the soaking pit. From time to time the cover is removed to allow :oldingots to be emplaced for heating and hot ingots to be emoved forrolling, and then the cover is replaced. The cover .s removed andreplaced by meansof a crane which travels along track beams located onopposite sides of the soaking pit, and the coping is subject to wear andtear each time that the cover is removed and replaced. Also, due to thehigh operating temperature and the periodical opening and closing of thesoaking pit, the refractory walls in the vicinity of the coping aresubjected to alternate heating and cooling. The marked changes intemperature cause the grooved coping blocks to crack and erosion ingeneral is pronounced at the high operating temperature. Withcontinuedoperation of the soaking pit, eventually the coping is damagedsufficiently to allow the sand in the coping trough to pour into theinterior of the furnace through cracks formed therein. Whenv thisoccurs, it is no longer possible to form a satisfactory seal with thelip on the soaking pit cover and it is necessary to repair the copingand replace the sand. The coping must be repaired at much more frequentintervals than the remaining refractory construction in the soakingpitand thus heretofore coping repairs were responsible for most of the downtime.

Prior to the present invention, it was necessary to remove the ingotcharge and shut down the soaking pit for at least a day and allow theinterior to cool gradually, to a temperature sufficiently low forworkmen to repair the coping from a portable scaffold. After the repairswere completed, the soaking pit was gradually heated back up to theoperating temperature. The soaking pit was out of service for at leastone to two days when using this method of coping repair. Additionally,the refractory construction in general was damaged due to the extremetemperature changes encountered over the cooling down and heating upcycles, and this tended to increase the frequency at which major repairshad to be made.

The usual routine repairs to the coping of a soaking pit may becompleted in only 1 to 2 hours after the workmen are able to enter thesoaking pit when using specialized modern equipment and materials. Thus,the prior art cooling and reheating cycles greatly increase the overallperiod of time that a soaking pit is out of service for coping repairs.As a result, the art I has long sought an entirely suitable method andapparatus whereby workmen may make repairs to the coping in safety andcomfort immediately after the soaking pit has been shut down, therebyavoiding the cooling and reheating cycles and reducing the down time toa few hours.

SUMMARY OF THE INVENTION The present invention provides an improvedwater-cooled platform which is adapted to be temporarily placed acresthe top of a soaking pit or other forms of top-opening furnaces wherebyworkmen may make repairs to the coping immediately after the furnace hasbeen shut down. The platform is constructed from a plurality ofwater-cooled platform members which are adapted to be fitted together soas to be adjustable transversely. This adjustable feature is importantas the platform width may be varied to compensate for changes whichinvariably occur in the original width of the soaking pit due to erosionof the refractory walls, the tendency of the refractory walls to sag orbow with age, etc.

The invention also provides a novel method of making repairs to thecoping of soaking pits and other types of topopening furnaces. Whenpracticing the method of the invention, workmen may commence repairingthe coping of a soaking pit immediately after the fuel has been shut offand the water-cooled platform of the invention has been set in place,thereby assuring that the soaking pit is out of service for a minimumperiod of time. The usual routine repairs to the coping may be made andthe soaking pit placed back in service in ing down and reheating cyclesof the prior art method, and

thereby markedly reduces the need for major repairs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pairof water-cooled platform members adapted to be fitted together alongtheir longitudinal dimension and used in constructing a water-cooledplatform in accordance with the invention;

FIG. 2 is a perspective view illustrating the water-cooled platformof-the invention in place across the opened top of a soaking pit;

FIG. 3 is a perspective view, with portions thereof being broken away toillustrate details within the interior of .the water-cooled platformmembers, wherein one of the platform members is shown in place acrossthe opened top of a soaking pit and the other is shown as it is beinglowered into position;

FIG. 4 is a transverse cross-sectional view taken along the line 4-4 ofFIG. 3;

FIG. 5 is a longitudinal cross-sectional view, with portions thereofbeing broken away, taken along the line 5--5 of FIG. 4; and

FIG. 6 is an enlarged fragmentary longitudinal cross-sectional viewtaken along the line 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION INCLUDING PREFERRED EMBODIMENTSAND VARIANTS THEREOF Referring now to the drawings, the pair ofwater-cooled platform members 10 and 11 illustrated in FIG. 1 may beused in constructing the water-cooled platform 12 of the inventionwhich, as is best seen in FIGS. 2-5, is positioned in the uncoveredopening 14 of soaking pit 15. The soaking pit 15 has refractory walls16, and the coping 17 thereof is constructed of grooved coping blocks'18 which provide a continuous coping trough 19. As is best seen inFIGS. 4 and 5, the coping trough 19 is partially filled with sand 20 andthe coping 17 has damaged areas 21 which allow the sand to pour into thesoaking pit interior 22. The damaged coping 17 and the loss of sand fromtrough l9 prevent a satisfactory seal from being made with a removablecover which. is normally in place thereon when the soaking pit is firedand in operation for heating steel ingots to a hot rolling temperature.

The soaking pit cover, the usual crane and apparatus cooperatingtherewith for removing and replacing the soaking pit cover, the lowerportions of the soaking pit refractory walls 16, the burners andapparatus cooperating therewith for firing and heating the soaking pit15 may be in accordance with the prior art, and are omitted in theinterest of simplifying the drawings. The steel ingots to be heated,which are normally positioned within the soaking pit interior 22, alsohave been omitted from the drawings for this purpose.

As will be recognized by those skilled in this art, in normal operationthe soaking pit 15 is fired and the interior 22 contains steel ingotswhich are heated to a hot rolling temperature of about 2l502450 F. Thus,the soaking pit 15 is operated at an extremely high temperature and itis necessary to discontinue the firing thereof prior to repairing thedamaged coping areas 21. The hot ingots within the soaking pit interior22 may or may not be removed as desired. However, it is usuallypreferred to remove the hot ingots and replace them with cold ingots.Cold ingots are capable of absorbing a substantial amount of heat fromthe hot interior 22 and thereby reduce the heat load on the water-cooledplatform 12.

"The platform member 10 includes an elongated water tight steel shell 23which may be constructed from longitudinally extending top plates 24, 25and 26, bottom plate 27, intermediate plate 28 and side plates 29, 30and 31, and transversely extending end plates 32 and 33. The interior ofshell 23 is reinforced by a longitudinally extending I-beam 35 which isof a length to abut the end plates 32 and 33. The reinforcing I- beam 35preferably is welded to the spaced top plates 24 and 26, bottom plate27, and/or end plates 32 and 33. Inasmuch as the top plates 24 and 26and bottom plate 27 rest on the top and bottom surfaces of I-beam 35,respectively, this results in the division of the interior of the shell23 into two longitudinally extending water passageways 36 and 37.Cooling water is supplied to water passageways 36 and 37 via waterconduits 38 and 39, respectively, and after passing therethrough, thewater is withdrawn via water outlet conduits 40 and 41, respectively.

A series of spaced baffles 42 is provided in water passageway 36, and asimilar series of baffles 43 is provided in water passageway 37. Thebaffles 42 and 43 extend transversely from the side plates 30 and 29,respectively, to the reinforcing I- beam 35 and abut the same at eitherend. As is best seen in FIGS. 3 and 5, the series of baffles 42 and 43are arranged whereby the flow of water through the water passageways 36and 37 is directed alternately upward onto the under surface of the topplates 24 and 26, respectively, and downward onto the upper surface ofbottom plate 27. For instance every other baffle member 42 and 43 iswelded to the under surfaces of top plates 24 and 26 and extend downwardtherefrom to approximately one-half of the depth of the waterpassageways 36 and 37, respectively, and the next preceding orsucceeding baffle member 42 or 43 is welded to the internal surface ofthe bottom plate 27 and extends upward therefrom to approximatelyone-half of the depth of the water passageway 36 or 37. This arrangementreduces localized heating and assures that a more uniform temperaturelevel is maintained within the shell 23.

-The preferred method of constructing the shell 23 from plates 24-33 isby welding in the manner best seen in FIGS. 3, 4, and 6 of the drawings.For example, the side plates 29 and 30 may be welded to the right andleft side edges, respectively, of the upper surface of bottom plate 27,and arranged to extend upwardly therefrom and form substantially a 90angle therewith. The reinforcing l-beam 35 is also welded to the uppersurface of bottom plate 27, and it is positioned approximately equaldistances from side plates 29 and 30. The inner side edge ofintermediate plate 28 rests upon the top of side plate 30 and is weldedthereto, and plate 28 then extends outward from plate 30. The side plate31 is carried by the outer end of intermediate plate 28 and it is weldedthereto, ex-

tends upward therefrom, and is arranged to form substantially a angletherewith. Spaced posts 34 for supporting top plate 24 are welded on theupper surface of,the inner end of intermediate plate 28, and formsubstantially a 90 angle therewith. The outwardly projectinglongitudinally extending portion 48 above plate 28 cooperates with asomewhat similar portion 49 on platform member 11 and forms-anoverlapping adjusting means for varying the effective width oftheplatform 12.

The top plates 24 and 26 are spaced-apart along their inner side edgesat point 44 so as to provide access to the upper surface of reinforcingI-beam 35 for welding thereto; This arrangement allows the reinforcingI-beam 35 to be rigidly joined to the bottom plate 27 and to each of thetop plates 24 and 26 by welding, whereby a greater reinforcing effect isobtained and especially when taken in combination with the transverselyextending baffles 42 and 43. The plate 25 overlaps the inner side edgesof top plates 24 and 26 and is welded thereto for the purpose ofreinforcing the same. The outer ends of top plate 24 and 26 rest uponthe upper surfaces of side plates 31 and 29, respectively, and arewelded thereto. The end plates 32 and 33 extend transversely across therear and forward edges, respectively, of top plates 2426, bottom plate27 and side plates 2931, and are joined thereto by welding so as tocomplete the shell 23 and assure the water tight integrity thereof.

A pair of longitudinally extending supporting I-beams 45 and 46 restupon the upper surfaces of plates 24 and 26, respectively, and arewelded thereto. I-beams 45 and 46 are of a length substantially greaterthan the length of the shell 23. As is best seen in FIG. 2, the ends ofI-beams 45 and 46 extend a sufficient distance past the ends of theshell 23 to rest upon the coping 17 of soaking pit furnace 15 when theshell 23 is positioned within the opening 14. The l-beams 45 and 46 areprovided with rings 47 for use with crane hooks whereby the platformmember 10 may be positioned on soaking pit 15 or removed therefrom.

The arrangement of the plates 24-33 is such that longitudinallyextending horizontal planes passing through bottom plate 27, theintermediate plate 28, and the top plates 24, 25 and 26 are preferablysubstantially parallel. Similarly, longitudinally extending verticalplanes passing through side plates 29, 30 and 31 are preferablysubstantially parallel. The shell 23 is preferably of a length to bereceived in the opening 14in close fitting relationship as is best seenin FIG. 5, and is supported therein by I-beams 45 and 46 which rest uponthe coping 17. The upper surface of shell 23 is substantially level withthe upper surface of the coping 17 whereby the amount of heat that isradiated onto the surface of platform 12 is reduced. For instance, ifthe shell 23 should be supported in opening 14 substantially below theupper surface ofcoping 17, the hot refractory wall 16 and coping 17would be free to radiate much more heat onto the upper surface ofplatform 12. t

The platform members 10 and 11 are of similar construction with theexception of the location of the overlapping adjusting means 48 and 49,respectively, which extend longitudinally along one side thereof. Ifdesired, an adjusting means 48 or 49 may be provided along each side ofthe platform members 10 and 11. As is best seen in FIG. 4, the adjustingmeans 48 on platform member 10 extends outward beneath the top plate 24and is slidable over the top of adjusting means 49 on platform member11, thereby allowing the effective width of the platform 12 to be variedto fit the width of opening 14 in soaking pit 15. This is of importanceas the refractory wall 16 varies in width as it ages.

The platform member 11 likewise includes an elongated water tight steelshell 52 which is constructed from longitudinally extending top plates53, 54 and 55, bottom plate 56, intermediate plate 57, and side plates58, 59 and 60, and transversely extending end plates 61 and 62. Theinterior of shell 52 is reinforced by a longitudinally extending l-beam64 which preferably is welded to top plates 53 and 55, bottom plate 56and/or end plates 61 and 62. Inasmuch as top plates 53 and 55 and bottomplate 56 rest on the top and bottomsurfaces of reinforcing I-beam 64,respectively, the shell 52 is divided into longitudinally extendingwater passageways 65 and 66. Cooling water is supplied to waterpassageways 65 and 66 via water inlet conduits 67 and 68, respectively,and after passing therethrough, the water is withdrawn via water outletconduits 69 and 70, respectively. As is best seen in FIG. 3, coolingwater also passes through the longitudinally extending spaces 78 and 79within adjusting means 48 and 49, respectively.

passageway65, and a similar series of baffles 72 is provided in waterpassageway 66. The baffles 71 and 72 are similar in construction andarrangement to baffles 42 and 43 and extend transversely from the sideplates 58 and 60, respectively, to the reinforcing l-beam 64 and abutthe same at eitherend. The baffles 71 and 72 are arranged to direct theflow of water through the water passageways 65 and 66 in the same manneras was discussed previously for the baffles 42 and 43 in waterpassageways 36 and 37.

- When constructing the shell 52 from plates 53-62, the side plates 58and 59 may be welded to the left and right side edges, respectively, ofthe upper surface of bottom plate 56. The reinforcing l-beam 64 may alsobe welded to the upper surface of bottom plate 56 and is positionedapproximately equal distancesfrom side plates 58 and 59. The outer sideedge of intermediate plate 57 rests upon the top of side plate 59 and iswelded thereto, and the plate 57 then extends inward from plate 59. Theside plate 60 is carried by the inner end of ntermediate plate 57 and iswelded thereto and extends upward therefrom. Spaced posts 63 arepositioned on plate 56 under the inner end of intermediate plate 57whereby the intermediate plate 57, side plate 60 and the outer end oftop plate 55 are supported thereby.

The top plates 53 and 55 are spaced along their inner side edges atpoint 73 and are welded to the upper surface of reinforcing l-beam 64.The plate 54 overlaps the inner side edges of top plates 53 and 55 andis welded thereto for the purpose of reinforcing the same. The outerends of top plates 53 and 55 rest upon the upper surfaces of side plates58 and 69, respectively and are welded thereto. The end plates 61 and 62extend transversely across the rear and forward edges, respectively, oftop plates 53-55, bottom plate 56, and side plates 58--60 and are weldedthereto so as to complete the shell 52 and assure the water tightintegrity thereof.

A pair of spaced longitudinally extending supporting I- beams 74 and 75rest upon the upper surfaces of top plates 53 and 55, respectively, andare welded thereto; The supporting l-beams 74 and 75 have a length asdiscussed above for I- beams 45 and 46, and are provided with rings 76for use with crane hooks.

The water passageways 36, 37 and 78 in platform member 10, and the waterpassageways 65, 66 and 79 in platform member 11 are shown as beingfilled with water 50 and 77, respectively. Preferably, the water 50 and70 is present therein when the members and 11 are positioned on soakingpit 15, and immediately thereafter the flow of fresh-cooling water viawater inlet conduits 38 and 39 is commenced.

When practicing the method of the invention, the firing of an operatingsoaking pit for heating steel ingots to a hotrolling temperature isdiscontinued and the soaking pit cover is removed. The hot ingots may beremoved from the soaking pit interior 22 and replaced with cold ingots,if desired. Thereafter platform member 11 is placed on one side of theopening 14 in the manner illustrated in FIG. 3 of the drawings. Platformmember 10 is placed on the other side of the opening 14 and then thewidth of the resulting water-cooled platform 12 is adjusted to theposition shown in FIG. 4 so as to closely conform with the width of therefractory wall 16. The platform members 10 and 11 are filled with waterwhen placed on the soaking pit 15, and immediately thereafter quickrelease hose connections are attached to water inlet conduits 38, 39, 67

and 68 and fresh-cooling water is supplied thereto and A series ofspaced baffles 71 is provided in water withdrawn via water outletconduits 40, 41, 69 and 70, respectively The flow of cooling waterthrough the water passageways 36, 37, 65, 66, 78 and 79 preventstheplatform 12 from overheating. workmen may stand on the upper surface ofplatform 12 and repair the damaged coping 17in comfort immediately aftercommencing the flow of cooling water, and there is no need to wait forthe refractory walls 16 to cool. It is preferred that modern gunning orramming apparatus and commercially available materials for use therewithbe employed to repair the damaged coping 17 so as to complete the repairwork as soon as possible. The repairs to the coping l7 usually may becompleted in l to 2 hours, and the soaking pit 15 may be placed back inservice in about I to 3 hours. The refractory construction in the wall16 does not cool sufficiently in this period of time to result insubstantial damage due to temperature changes and the life of theoverall refractory construction is increased substantially.

Iclaim:

l. A water-cooled platform member for use in making repairs to ahot topopening furnace for heating ferrous metal charge stock includingrefractory walls having a coping comprising an elongated water tightshell, the shell having water passageway means for passing cooling waterthe'rethrough whereby the platform may be water cooled and an uppersurface on which workmen may stand when repairing the coping of afurnace, reinforcing means within the interior of the shell forreinforcing the same, means for supporting the shell within the openingin the furnace including at least one supporting beam, the supportingbeam being of a length substantially greater than the length of theshell, means for mounting the supporting beam above the upper surface ofthe shell, the supporting beam being mounted whereby it extendslongitudinally along the shell and above the said upper surface thereofand the outer end portions of the supporting beam extending past theends of the shell, the shell being of a length. whereby it may belowered into the opening of a furnace having a coping to be repaired,the supporting beam being of a length whereby it extends across the saidfurnace having the coping to be repaired with the said outer endportions thereof resting on the coping when the shell is lowered intothe furnace opening, means for introducing cooling water into the waterpassageway means in the shell, means for withdrawing water from the saidwater passageway means, and the shell having overlapping adjusting meansalong at least one side of the shell including a portion of the waterpassageway means whereby a plurality of the said platform members may befitted together in side by side relationship and the effective widththereof may be varied.

2. The platform member of claim 1 wherein baffle means is provided inthe said water passageway.

3. The platform member of claim 1 wherein the said shell is constructedof steel plates, the shell includes spaced longitudinally extending topand bottom plates, and the reinforcing means includes a longitudinallyextending steel-reinforcing beam positioned between the top and bottomplates and intermediate the side edges thereof.

4. The platform member of claim 3 wherein the said shell includes spacedlongitudinally extending steel side plates, and the bafile meansincludes steel baffle members extending transversely between thereinforcing beam and the side plates.

5. The platform member of claim 4 wherein the shell includes spacedtransversely extending steel end plates, the ends of the reinforcingbeam abut the end plates, the ends of the baffle members abut thereinforcing beam and the side plates and the reinforcing beam is rigidlyattached to the top and bottom plates whereby the said shell iseffectively reinforced thereby.

6. The platform member of claim 5 wherein the supporting beam and thereinforcing beam are l-beams, the top and bottom portions of thereinforcing l-beam are joined to the top and bottom plates whereby theshell is divided into two longitudinally extending water passageways,the means for introducing cooling water includes means for introducingcooling water into one end of each of the said two water passageways andthe means for withdrawing water includes means for withdrawing waterfrom the other ends thereof whereby the cooling water is caused to passthrough the two water passageways, the means for supporting the shell inthe furnace includes two spaced supporting I-beams which are positionedabove the top plate and one of the supporting lbeams is above each ofthe two water passageways.

7. A water-cooled platform for use in making repairs to a hottop-opening furnace for heating ferrous metal charge stock includingrefractory walls having a coping, the platform including at least twoplatform members, each of said platform members comprising an elongatedwater-tight shell, the shell having water passageway means for passingcooling water therethrough whereby the platform may be water cooled andan upper surface area on which workmen may stand when repairing thecoping of a furnace, reinforcing means within the interior of the shellfor reinforcing the same, means for supporting the shell within theopening in the furnace including at least one supporting beam, thesupporting beam being of a length substantially greater than the lengthof the shell, means for mounting the supporting beam above the uppersurface of the shell the supporting beam being mounted whereby itextends longitudinally along the shell and above the said upper surfacethereof and the outer end portions of the supporting beam extending pastthe ends of the shell, the shell being of a length whereby it may belowered into the opening of a furnace having a coping to be repaired,the supporting beam being of a length whereby it extends across the saidfurnace having the coping to be repaired with the said outer endportions thereof resting on the coping when the shell is lowered intothe furnace opening, means for introducing cooling water into the waterpassageway means in the shell, means for withdrawing water from the saidwater passageway means, and the shell having overlapping adjusting meansalong at least one side of the shell including a portion of the waterpassageway means whereby a plurality of the said platform members may befitted together in side by side relationship and the effective 8. Thewater-cooled platform of claim 7 wherein baffle,

means is provided in the said water passageway means.

9. The water-cooled platform of claim 7"wherein the said j shell isconstructed of steel plates, the shell includes spaced longitudinallyextending top and bottom plates, and the reinforcing means includes alongitudinally extending steel-reinforcing beam positioned betweenthetop and bottom plates and intennediate the side edgesthereof.

10. The water-cooled platform of claim 9 wherein the said shell includesspaced longitudinally extending steel side plates, and the baffle meansincludes steel baffle members'extending transversely between thereinforcing beam and the side plates.

11. The water-cooled platform of claim 10 wherein the shell includesspaced transversely extending steel end plates, the ends of thereinforcing beam abut the end plates, the ends of the baffle membersabut the reinforcing beam and the side plates and the reinforcing beamis rigidly attached to the top and bottom plates whereby the said shellis effectively reinforced thereby.

12. The water-cooled platform of claim 11 wherein the supporting beamand the reinforcing beam are l-beams, the top and bottom portions of thereinforcing l-beam are joined to the top and bottom plates whereby theshell is divided into two longitudinally extending water passageways,the means for introducing cooling water includes means for introducingcooling water into one end of each of the said two water passageways andthe means for withdrawing water includes means for withdrawing waterfrom the other ends thereof whereby the cooling water is caused to passthrough the two water passageways, the means for supporting the shell inthe furnace includes two spaced supporting l-beams which are positionedabove the top plate and one of the supporting beams is above each of thetwo water passageways.

